1. Field of the Invention
The present invention relates to a method for rehabilitating an existing pipe, and more specifically to a method for rehabilitating an existing pipe, wherein segments are coupled in circumferential and vertical directions, and laid as a rehabilitating pipe inside the vertically extending existing pipe, such as a manhole.
2. Description of the Prior Art
A method of rehabilitating a vertically extending existing pipe, such as a manhole, is known from Japanese Patent Laid Open Publication No. 1996-150659. This discloses a method that rehabilitates a manhole by lining the inner circumferential surface of the manhole by inserting into the manhole a lining material comprising a pipe shaped flexible resin absorbing material impregnated with a liquid setting resin. The lining material is pressed against the inner circumferential surface of the manhole by the pressure of a fluid, such as water, so that it takes a shape identical to the inner circumferential surface of the manhole. The setting resin is then cured to provide a rehabilitating pipe for the manhole.
In such a method, the lining material is inserted into the manhole, extending across the entire length thereof and the inner surface of the manhole is lined all at once; therefore, although the lining can be completed in a short period of time, there is a disadvantage in that the rehabilitation work cannot be carried out while viewing the appearance of the inner wall surface of the manhole and repetitively performing partial repairs.
Japanese Patent Laid Open Publication No. 2003-286742 discloses a method that rehabilitates an existing pipe by successively coupling segments in the circumferential direction and in the pipe longitudinal direction. One segment comprises two side plates and two end plates that are integrally provided upright at a prescribed height on an inner plate. In this method, the entirety can be repaired while performing partial repairs, but there is the disadvantage in that all segments must be coupled during assembly in the circumferential direction and in the pipe longitudinal direction using a coupling means, thereby complicating the pipe laying.
It is therefore an object of the present invention to provide a method for rehabilitating a vertically extending existing pipe such as a manhole, enabling, with a simple constitution, the successive repair of the existing pipe while viewing the state of an inner wall surface thereof.